1959 年 9 巻 4 号 p. 772-785
The statistical survey has been made on the forty-six cases of the childhood mutism from among the 24, 245 pupils of the whole elementary schools in the City M., by means of the diagnostic interview and the questionnaire method. The childhood mutisms were observed Tin 0.19% of the whole pupils, girls exceeding boys in the frequency.
The personal and environmental factors which may bring about anxiety and feeling of isolation on the part of the patients producing negativistic responses such as mutism are as follows :
The personal factors contributing to infantile mutism were intellectual retardation and consequently poor academic achievement with delayed commencement of speech and walking. Notable diseases in the past, and nervous habits in the past and present are often considered as contributing factors. Although the problem of the heredity of the mutistic trends needs further considerations, patients' near relatives surveyed showed comparatively frequent occurrences of mutism. The psychiatric survey of the patients' present physical conditions revealed no direct relationships with mutism, with the exceptions of some physical indications for some of the mentally deficient subjects.
As for environmental factors, the attitudes of their parents' laissez-faire and their mothers' over-protection may be influential in producing mutism. It was noticed that the academic career and socio-economic status of the parents were considerably low. Among the effects of the grandparents' attitudes contributing to the formation of the symptom, the grandmothers' over-protection should be emphasized. In some cases, sibling rivalry might also be regarded as a factor, but in this respect, further observation may be demanded. The numbers of the patients' friends and playmates are remarkably few, which might in turn promote the mutistic trends. Situations causing the childhood mutism are found chiefly in and around schools and unacquainted places, being scarcely seen in the home and neighbourhood situations.